AD538BD

实时模拟计算单元ACU Real-Time Analog Computational Unit ACU

Product Details

The AD538 is a monolithic real-time computational circuit which provides precision analog multiplication, division, and exponentiation. The combination of low input and output offset voltages and excellent linearity results in accurate computation over an unusually wide input dynamic range. Laser wafer trimming makes multiplication and division with errors as low as 0.25% of reading possible, while typical output offsets of 100 microV or less add to the overall off-the-shelf performance level. Real-time analog signal processing is further enhanced by the device"s 400 kHz bandwidth.

The AD538"s overall transfer function is Vo=VyVz/Vxm. Programming a particular function is via pin strapping. No external components are required for one-quadrant positive input multiplication and division. Two-quadrant bipolar numerator division is possible with the use of external level shifting and scaling resistors. The desired scale factor for both multiplication and division can be set using the on-chip +2 V or +10 V references, or controlled externally to provide simultaneous multiplication and division. Exponentiation with an M value from 0.2 to 5 can be implemented with the addition of one or two external resistors.

Direct log ratio computation is possible by utilizing only the log ratio and output sections of the chip. Access to the multiple summing junctions adds further to the AD538"s flexibility. Finally, a wide power-supply range of ±4.5 V to ±18 V allows operation from standard ±5 V, ± 12 V and ± 15 V supplies.

The AD538 is available in two accuracy grades A and B over the industrial -25°C to +85°C temperature range and one grade S over the military -55°C to +125°C temperature range. The device is packaged in an 18-pin TO-118 hermetic size-brazed ceramic DIP. A-grade chips are also available.

### Features and Benefits

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VOUT = VY VZ divided by VXm Transfer Function

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Wide Dynamic Range Denominator -1000:1

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Simultaneous Multiplication and Division

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Resistor-Programmable Powers and Roots

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No External Trims Required

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Low Input Offsets <100 µV

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Low Error ±0.25% of Reading 100:1 Range

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+2 V and +10 V On-Chip References

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Monolithic Construction